Keystore: Fix made to use the copy of the input parameter passed to

checkEntropy helper method.

checkEntropy method internally modifies the parameter passed to it so
while performing entropy check for verifiedBootHash and verifiedBootkey,
copy of verifiedBootkey and VerifiedBootHash values are used.

Bug: 335081121
Test: atest android.keystore.cts.KeyAttestationTest
Change-Id: I9921b788652bc754093fb951c679005f26f53ec5

1 files changed, 10 insertions, 3 deletions

diff --git a/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java b/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
index f27b44579eb..6903e949696 100644
--- a/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
+++ b/tests/tests/keystore/src/android/keystore/cts/KeyAttestationTest.java
@@ -1701,9 +1701,10 @@ public class KeyAttestationTest {
         }
     }
 
-    private void checkEntropy(byte[] verifiedBootKey) {
-        assertTrue("Failed Shannon entropy check", checkShannonEntropy(verifiedBootKey));
-        assertTrue("Failed BiEntropy check", checkTresBiEntropy(verifiedBootKey));
+    private void checkEntropy(byte[] entropyData) {
+        byte[] entropyDataCopy = Arrays.copyOf(entropyData, entropyData.length);
+        assertTrue("Failed Shannon entropy check", checkShannonEntropy(entropyDataCopy));
+        assertTrue("Failed BiEntropy check", checkTresBiEntropy(entropyDataCopy));
     }
 
     private boolean checkShannonEntropy(byte[] verifiedBootKey) {
@@ -1719,6 +1720,9 @@ public class KeyAttestationTest {
         return entropy;
     }
 
+    /**
+     * Note: This method modifies the input parameter while performing bit entropy check.
+     */
     private boolean checkTresBiEntropy(byte[] verifiedBootKey) {
         double weightingFactor = 0;
         double weightedEntropy = 0;
@@ -1736,6 +1740,9 @@ public class KeyAttestationTest {
         return tresBiEntropy > 0.9;
     }
 
+    /**
+     * Note: This method modifies the input parameter - bitString.
+     */
     private void deriveBitString(byte[] bitString, int activeLength) {
         int length = activeLength / 8;
         if (activeLength % 8 != 0) {